Great Western Electrification Progress

[LNW-GW Joint]

I think you could be wrong there Phil? Looks like earth wire to me as its sliver colour and under the boom, although don't know why its going into a insulator?

The NR press item says it is indeed an earth wire.
http://www.networkrailmediacentre.c...ication-wiring-on-the-great-western-main-line

Last night, Thursday 12 November, Network Rail engineers installed the first overhead wires for the electrification of the Great Western Main Line.
One mile, or 1.6km, of earth wire was installed on the lines west of Reading between Pangbourne and Tilehurst, part of the track that will serve as a test section for the new Class 800 Intercity Express trains.
This is the first section of the new-design overhead line to be erected on the operational railway, and the first overhead line anywhere on the route beyond the existing wires at Airport Junction in Stockley, London. The first 1,000 metres were installed in only 35 minutes

 

[swt_passenger]

I think you could be wrong there Phil? Looks like earth wire to me as its sliver colour and under the boom, although don't know why its going into a insulator?

Isn't it on insulators because on an ATF system it has a slightly different purpose, therefore it isn't fitted the same way as a conventional earth return conductor? Hopefully someone will know the exact reason.

 

[GRALISTAIR]

Psychologically good - really great news.

How soon before the politicians chime in?

 

[steverailer]

Isn't it on insulators because on an ATF system it has a slightly different purpose, therefore it isn't fitted the same way as a conventional earth return conductor? Hopefully someone will know the exact reason.

All the ones I've installed the earth is direct to steel, no insulator at all. Thats in NW and WCML. Undertand series one is the same

 

[po8crg]

It's easy to gain 12 inches in many cases.

That's what they keep emailing to tell me!

(Sorry)

 

[Philip Phlopp]

I think you could be wrong there Phil? Looks like earth wire to me as its sliver colour and under the boom, although don't know why its going into a insulator?

Yeah, earth wire as per PR release. I was going to go back and fix my post but got sidetracked trying to find out who's doing the Maidenhead to Reading (and slightly beyond) wiring.

 

[steverailer]

Yeah, earth wire as per PR release. I was going to go back and fix my post but got sidetracked trying to find out who's doing the Maidenhead to Reading (and slightly beyond) wiring.

Believe its Amey, being installed coventionally by SRS Rail is the rummour I have heard, just waiting for piling to get far enough infront so my contacts say

 

[LNW-GW Joint]

Believe its Amey, being installed coventionally by SRS Rail is the rummour I have heard, just waiting for piling to get far enough infront so my contacts say

It says Keltbray on the RRV in the pic.
They pop up everywhere (Norton Bridge for instance, which has significant wiring work).

 

[steverailer]

It says Keltbray on the RRV in the pic.
They pop up everywhere (Norton Bridge for instance, which has significant wiring work).

From what I understand Keltbray are doing Tilehurst to Pangbourne, SRS Pangbourne to Didcot and Maidenhead to Reading.

My comment was in reply to Phillip asking about the Maidenhead to Reading section, not the picture. And yes they do get everywhere, but don't have the best reputation they were on the WCML PSU work until ABC took over as it was 12 months behind

 

[Class 170101]

Yes and no - wiring extending from Airport Junction could go live earlier but this serves no real purpose, other than a little testing work.

How about livening it up to stop the scroats nicking it?

 

[Ironside]

How about livening it up to stop the scroats nicking it?

Does that still happen? I thought the changes to the way the scap industry works had got rid of that sort of thing.

 

[furnessvale]

How about livening it up to stop the scroats nicking it?

A scroat was once fried trying to nick the OHLE from the disused Godley sidings on the Woodhead route.

At his inquest the coroner asked why the wires were still alive if the sidings were out of use. The railway witness said truthfully "to deter thieves".

The coroner said (words to the effect), "what a good idea".

Imagine that in today's compensation culture world.

 

[Tw99]

I'll have to go for a walk tomorrow and do some wire-spotting. This must be within a mile of my house.

 

[swt_passenger]

How about livening it up to stop the scroats nicking it?

It wouldn't stay live for long if they livened up an 'earth wire' (as stated above). Might be a good test of some circuit breakers I guess...

 

[Envoy]

Deleted - loaded to wrong forum.

 

[sprinterguy]

When HS 2 is built, are we going to have larger trains that would not be able to 'fit' on the north Wales Main Line in any case - thus requiring a change of trains at Crewe? Alternatively, would they build a fleet to smaller dimensions for travelling off the new HS 2 route?

Getting a fair way off topic from GWML electrification here (Was this post intended for this thead here? http://www.railforums.co.uk/showthread.php?t=123233), but the HS2 train fleet will comprise both "captive" trainsets that take advantage of the larger loading gauge, and "classic compatible" sets that will be able to continue their journeys on the existing network.

 

[Tw99]

I went out and had a look at this first stretch of wiring this morning. They seem to have done a bit more since that tweet, as there's three wires up in the area I was looking at. It's located a few hundred metres west of the Westbury Lane bridge at Purley on Thames, so between there and Pangbourne.

There are quite a few different types of portal with different equipment attached, not all of which I understand, so perhaps someone can fill in the details.

This is one of the braced portals with the tensioning spools on it:

Quite a lot of the portals are like this, with pairs of cantilevered booms, one set on each side, so eight in total.

Others just have a single set of booms:

And then there's this odd one that has no cantilevers, but just individual poles above each track. It's braced, too.

 

[swt_passenger]

There are quite a few different types of portal with different equipment attached, not all of which I understand, so perhaps someone can fill in the details.

They'll have two complete sets of insulators and registration arms (hence 8 sets per gantry) during the overlap between adjacent wiring runs, where there is a distance with 8 catenaries and 8 contact wires..

Not sure about the design distance between the sets of tensioning gear and line terminating equipment, but they'll be a few hundred yards apart so the doubling up will include a few successive gantries.

The wires shown in your pictures are the catenary wires that run above the insulated arm, the contact wires will be vertically below them attached by the droppers and laterally restrained by the registration arms. The registration arms are visible but tied up, and there are a few droppers shown, the small coils clipped to the catenary here and there.

I'd recommend the series of photos lower down on this web page that show the various components in their eventual positions: http://www.furrerfrey.ch/en/systems/Series-1.html
The second image shows a two track cantilever and probably explains what you are looking at - you just have to imagine it doubled up for a four track gantry and then doubled again for the wiring run overlap.

Hope that helps.

 

[Philip Phlopp]

Not sure about the design distance between the sets of tensioning equipment, but they'll be a few hundred yards apart so the doubling up will include a few successive gantries..

The system is designed for a single span overlap, to avoid too many portals and doubled up catenary elements. Operation requirements will require changes in places.

The curious looking gantry is for sectioning and feeding arrangements.

 

[steverailer]

The system is designed for a single span overlap, to avoid too many portals and doubled up catenary elements. Operation requirements will require changes in places.

The curious looking gantry is for sectioning and feeding arrangements.

Think the majority of the line from Tilehurst to Didcot has 3 span overlaps Phillip, i.e 2 portals in between the sets of tensorex ones.

The last picture is the mid-point anchor portal, its missing the registration arms on the insulators below the boom

 

[swt_passenger]

Think the majority of the line from Tilehurst to Didcot has 3 span overlaps Phillip, i.e 2 portals in between the sets of tensorex ones.

I was wondering if the tensorex units are fitted at both ends of each wire run? I'm assuming that at both ends would be the best way of doing it - so that the mid point of a wire run didn't move much - but it would be interesting to know for certain.

 

[steverailer]

I was wondering if the tensorex units are fitted at both ends of each wire run? I'm assuming that at both ends would be the best way of doing it - so that the mid point of a wire run didn't move much - but it would be interesting to know for certain.

Yes there is a set at each end of a run, the caterary is fixed at the mid point and 'z' droppers used to fix the Contact (a length of catenary wire fastened near the mid point connection at the catenary then tensioned down to the contact roughly 20m away) The fixing at the mid point stops the 2 sets of tensorex fighting against each other, one with more and one with less ect, same as on a balance weight set up

There will only be one set on a cross over or short run such as a sidings ect

 

[swt_passenger]

Yes there is a set at each end of a run, the caterary is fixed at the mid point and 'z' droppers used to fix the Contact (a length of catenary wire fastened near the mid point connection at the catenary then tensioned down to the contact roughly 20m away) The fixing at the mid point stops the 2 sets of tensorex fighting against each other, one with more and one with less ect, same as on a balance weight set up

There will only be one set on a cross over or short run such as a sidings ect

Thanks for the info, I should nearly be in a position to put my own system up...

 

[Philip Phlopp]

Think the majority of the line from Tilehurst to Didcot has 3 span overlaps Phillip, i.e 2 portals in between the sets of tensorex ones.

The last picture is the mid-point anchor portal, its missing the registration arms on the insulators below the boom

It's being done with 3 span overlaps through Berkshire too, but that really isn't what was intended, not that it makes any difference.

Yeah, had a proper look at the bottom picture (first one I've had a proper look at in-situ) and as you say, it's missing the cantilevers and from what I can see, it's got the wire mounting insulators pointing in the wrong direction for the wire runs at the moment, but that will just be to keep them out of the way for now.

 

[Ploughman]

In that first photo haven't they forgotten to cut the vegetation back?

 

[Tw99]

In that first photo haven't they forgotten to cut the vegetation back?

There's still a lot of work going on removing vegetation in this area.

 

[Mintona]

In a different area, piling appears to be nearly finished between Pilning station and Patchway tunnel, and is now starting to appear the other side of Pilning down towards the Severn Tunnel. There are also far more piles around Llanwern West than previously too, almost extending to Bishton crossing alongside the up main. Seem to be getting on with it down that way fairly quickly now.

 

[HowardGWR]

In a different area, piling appears to be nearly finished between Pilning station and Patchway tunnel, and is now starting to appear the other side of Pilning down towards the Severn Tunnel. There are also far more piles around Llanwern West than previously too, almost extending to Bishton crossing alongside the up main. Seem to be getting on with it down that way fairly quickly now.

Does Bristol box control Pilning? If so, I assume that the location of cabling is not as mysterious as @Philip Phlopp fears, in another post of his.

Is there a date for when Bristol box is to be removed? I shall rejoice when that happens and the old station is available for update.

 

[LNW-GW Joint]

Does Bristol box control Pilning? If so, I assume that the location of cabling is not as mysterious as @Philip Phlopp fears, in another post of his.
Is there a date for when Bristol box is to be removed? I shall rejoice when that happens and the old station is available for update.

No to the former, the line from Patchway westwards was resignalled relatively recently into South Wales CC at Cardiff, and the line is now formally part of NR's Wales Route.
It's also why NR has started piling work along this stretch - they know where the cables are.

On the latter - dunno.
The Badminton-Patchway section is being resignalled now, but I don't think anywhere else is very advanced.

 

[Tw99]

The contact wire is now installed over the up relief line on that same short section.